Agricultural vehicle cab fitted with an hvac system

ABSTRACT

A cab of an agricultural vehicle has having a seat for an operator and a console unit arranged forward of the seat for housing an instrument display. The cab is fitted with an HVAC system comprising a heat exchanger unit located within the console unit and a blower located on the floor of the cab beneath or adjacent the seat and serving to blow air by way of a floor-level duct to the heat exchanger unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/805,364, entitled “AGRICULTURAL VEHICLE CAB FITTED WITH AN HVACSYSTEM”, filed on Mar. 28, 2013, which is the US National Stage filingof International Application Serial No. PCT/EP2011/060997, entitled“AGRICULTURAL VEHICLE CAB FITTED WITH AN HVAC SYSTEM,” filed on Jun. 30,2011, which claims priority to Italian Application Serial No.TO2010A000569, filed Jul. 2, 2010, each of which is incorporated hereinby reference in its entirety for all purposes.

FIELD OF THE INVENTION

The present invention relates to a heating, ventilation and airconditioning (HVAC) system fitted to the cab of an off-highway vehicle,this term being used to include agricultural vehicles such as tractorsand harvesters and construction machine such as excavators andtelehandlers.

BACKGROUND OF THE INVENTION

As is known, the essential components of a vehicle HVAC system includean air inlet, a filter for removing dust and dirt particles from theintake air, a blower, a heat exchanger unit which may include at leastone of an evaporator through which flows the refrigerant of arefrigeration circuit and a radiator through which flows a heated liquid(usually that circulating in the engine cooling system), and air ventsfor discharging air into the cab after it has been filtered and blownthrough the heat exchanger unit by the blower.

The design and location of the HVAC system of an off-highway vehicle,requires careful consideration on account of the limited space availablewithin the cab.

Because off-highway vehicles often operate in a dirty environment, it ispreferable for the air intake to be located at rooftop level and acompact configuration that is sometimes adopted is to place all thecomponents of the HVAC system in a roof mounted unit. However, this issometimes not possible, for example if the cab has an opening roof or ifthe HVAC unit would restrict visibility unacceptably.

An alternative solution that has been proposed is to place the blowerand the heat exchanger unit beneath the seat of the operator but thattoo is not always practicable. In particular, in some vehicles theclearance between the seat and the floor of the cab is not large enoughto accommodate the heat exchanger unit and the blower. Furthermore, insuch a configuration the air in the duct may be heated while flowingfrom the heat exchanger unit to vents in the console unit or dashboard.

Another solution would be to have the HVAC located partly within thecabin and partly in the engine bay but this would expose the componentsof the HVAC system to a dirt environment and to higher temperatures andwould take up valuable packaging space within the engine bay.

OBJECT OF THE INVENTION

The present invention seeks therefore to provide an HVAC system for thecab of an off-highway vehicle that mitigates at least some of theforegoing disadvantages and enables the system to be integrated into cabin a space efficient manner without obstructing visibility and withouttaking up excessive space within the cab.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there isprovided a cab of an off-highway vehicle having a seat for an operatorand a console unit arranged forward of the seat for housing aninstrument display, wherein the cab is fitted with an HVAC systemcomprising a heat exchanger unit located within the console unit and ablower located on the floor of the cab beneath or adjacent the seat andserving to blow air by way of a floor-level duct to the heat exchangerunit.

Discharge vents may suitably be mounted in the console unit to directthe air passing through the heat exchanger unit towards the operator.

Preferably, the air supply to the blower passes through a filter unitlocated within a wheel fender of the vehicle.

Advantageously, both plenum boxes of the filter unit, namely the dirtybox upstream of the filter element and the clean box downstream of thefilter element, are housed within the wheel fender. The air from theclean box may suitably be guided to the blower by way of a duct disposedwithin the cab and following the contour of the wheel fender.

The air intake of the HVAC system is preferably located on the outsideof the cab at roof level and flows to the intake filter by way of avertical duct, the latter being conveniently constituted by the B-pillarof the cab.

In a preferred embodiment of the invention, a second filter is provided,to allow the blower to draw filtered air from the interior of the cabfor recirculation through the heat exchanger unit, in addition to or inplace of the air drawn through the first filter.

In a second aspect of the invention, there is a provided an HVAC systemfor an off-highway vehicle having a blower for blowing air through aheat exchanger unit and a filter unit arranged upstream of the blower tofilter the air blown by the blower, the filter unit comprising a dirtybox and a clean box separated from one another by a filter element,characterised in that the entire filter unit is housed within a wheelfender of the vehicle.

Advantageously, the wheel fender include a removable panel that servesas a wall of the filter unit and, when removed, allows access to theinterior of the filter unit for replacement of the filter element.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a front perspective view of the cab of a tractor,

FIG. 2 is a side view of the cab shown in FIG. 1 indicating the locationof the components of the HVAC system,

FIG. 3 is a rear perspective view of the cab in FIG. 2,

FIG. 4 is a schematic representation of the cab shown in FIGS. 2 and 3,and

FIGS. 5 and 6 are sectional plan and side views, respectively, of afilter unit mounted within a wheel fender.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The cab 10 shown in FIGS. 1 to 4 has a floor 12, a roof 14 and A, B andC pillars supporting the roof 14, these being designated 16, 18 and 20,respectively. A wheel fender 22 is arranged on each side of the cab. Theseat 60 for the driver, which is located centrally within the cab, hasbeen omitted from FIGS. 1 to 3 but is shown in FIG. 4.

Forward of the seat 60, the cab contains a steering wheel 24 and aconsole unit 26. The console unit 26 houses the various instrumentsneeded by the driver, such as the speedometer and various gauges, and itmay also be used for mounting various switches and control knobs thatare needed by the driver. It will be appreciated that this design of cabis entirely conventional and the invention is not concerned with thedesign of the cab itself but with the manner in which an HVAC system maybe built into the cab.

The doors of the cab are mounted between the A and B pillars 16, 18 andas can be seen from FIG. 1 the roof 14 overhangs the door openings. Theair for the HVAC system in the preferred embodiment of the invention isdrawn in through grills located on the underside of the overhangingportions of the roof 14, as shown schematically in FIG. 4 where the airflow is represented by arrows. As the air enters the HVAC system at rooflevel, it contains less dust than it would if the intake grills werelocated closer to the ground.

The intake air flows down the B pillar 18 to an air filter unit 30located within the wheel fender 22. As shown in FIGS. 5 and 6, the airfilter unit 30 comprises two plenum chambers 70 and 72 separated fromone another by a filter element 71, these being referred to commonly asthe dirty box and the clean box, respectively. In the preferredembodiment of the invention, both boxes 70 and 72 as well as the filterelement are housed within the wheel fender 22. The top of the wheelfender has a removable access cover 76, shown in FIG. 6, to allowreplacement of the filter element 71. The dirty box 70 communicatesdirectly with the interior of the B pillar 18 whereas the clean boxcommunicates with a conduit 74 arranged within the cab and following thecontour of the wheel fender 22.

A blower 32 is arranged on the floor 12 of the cab adjacent and to oneside, or beneath, the seat of the driver. In the embodiment of theinvention shown in FIG. 3, two such blower are provided and disposed oneon each side of the driver seat 60. The intake of the or each blower 32is connected to the conduit 74 connected to the clean box of the filterunit 30 and its outlet communicates with a second conduit 34 that isbuilt into the floor 12 of the cab. The conduit 34 is arranged on theunderside of the floor. If the conduit 34 needs to pass adjacent any hotelements, such as an exhaust system, then it can be thermally insulated.

As shown in FIG. 4, a second filter 80 can be provided to allow theblower 32 to draw filtered air from the interior of the cab forrecirculation through the heat exchanger unit, in addition to or inplace of the air drawn through the first filter 30. Air recirculation isbetter suited to extremes of hot and cold conditions because of themultiple passes of the same air through the heat exchanger unit, whereasfresh air is to be preferred under other conditions. A flap may beprovided to allow the driver to vary the relative proportions ofrecirculated air and fresh air flowing through the HVAC system.

The heat exchanger unit 36 is mounted in the console unit 26 on thefront of the cab. As the engine bay 50, which houses the engine 52 aswell as the compressor 54 and the evaporator 56 of the HVAC system isalso located at the front the vehicle, the lengths of the pipes whichconvey a refrigeration coolant or hot water from the engine coolingsystem to the radiators of the heat exchanger unit 36 are minimised.Conduits within the console unit 26 guide the air blown by the blower 32past the heat exchanger unit 36 to be discharged into the cab by way ofair vents formed in the console unit 26. As represented by the arrows inFIG. 4, the air vents may be located to blow air towards the windscreenfor defrosting/demisting or towards the face or the feet of the seatedoperator.

As is shown in FIG. 3, the entire HVAC system may be symmetrical, usingtwo air filters 30 as well as two blowers 32 arranged one on each sideof the cab 10.

By separating the blower(s) from the heat exchanger unit, the inventionallows the space behind the console unit 26 to be used to accommodatethe heat exchanger unit. This is an ideal location in terms of itsproximity to the engine compartment for optimal routing of therefrigerant and coolant lines and to the discharge air vents. The spaceon each side of the driver's seat 60 provides ample room for mounting ablower without restricting the driver's access.

The preferred embodiment of the invention offers the further advantagethat the filter unit is located outside the cab in a space that normallyserves no functional purpose, namely the space within the wheel fender.Furthermore, the installation of the HVAC system into the cab issimplified by using the B-pillar to convey the air from the roof mountedintake grille to the dirty box 70 of the filter unit 30.

1. A cab of an off-highway agricultural vehicle, the cab extendingbetween a forward end configured to be located aft of an engine bay ofthe off-highway agricultural vehicle and an aft end opposite the forwardend, the cab comprising: a roof having an intake opening formed along aportion of the roof; a floor; a plurality of pillars, wherein at leastone pillar of the plurality of pillars is positioned between a forwardend pillar of the plurality of pillars and a back end pillar of theplurality of pillars, the at least one pillar connects the roof and thefloor and is configured to support the roof, and only the at least onepillar forms a respective duct configured to receive air from the intakeopening positioned above the at least one pillar; a seat for an operatorsupported within the cab; and a console unit arranged forward of theseat at a location adjacent to the forward end of the cab and configuredto house an instrument display, wherein the cab is fitted with aheating, ventilation and air conditioning (HVAC) system including: aheat exchanger unit located within the console unit so as to bepositioned between the forward and aft ends of the cab; a filter unitconfigured to receive the air directed to the heat exchanger unit,wherein the filter unit is positioned between a top surface of a wheelfender positioned on the outside of the cab and an adjacent wheel of theoff-highway agricultural vehicle, and the respective duct formed by theat least one pillar is configured to direct the air from the intakeopening of the roof to the filter unit; a blower configured to providethe air to the heat exchanger unit, wherein the blower is located on thefloor of the cab, separate from the console unit, beneath or adjacentthe seat and is connected to the heat exchanger unit by way of afloor-level conduit, and the floor-level conduit extends through atleast a portion of the floor; and a filter unit conduit extendingbetween the filter unit and the blower, and the floor-level conduitextending between the blower and the heat exchanger.
 2. The cab of claim1, wherein discharge vents are mounted in the console unit to direct theair passing through the heat exchanger unit toward the operator.
 3. Thecab of claim 1, wherein the at least one pillar is positioned next to adoor of the cab.
 4. The cab of claim 1, wherein the filter unit has aclean box and a dirty box separated from one another by a filterelement, and wherein the clean and dirty boxes of the filter unit arehoused within the wheel fender.
 5. The cab of claim 4, wherein thefilter unit conduit is disposed within the cab, the filter unit conduitis configured to guide the air from the clean box to the blower, and thefilter unit conduit curves to follow a curved contour of the wheelfender.
 6. The cab of claim 4, comprising an access cover positionedadjacent to the top surface of the wheel fender, wherein the accesscover is removable from the wheel fender to enable access to the filterelement.
 7. The cab of claim 1, wherein the intake opening is formedalong an underside of the roof of the cab.
 8. A cab of a work vehicle,comprising: a roof having an intake opening formed along a portion ofthe roof; a floor; a pillar extending between the roof and the floor,wherein the pillar is configured to support the roof, and the pillaralone forms a duct configured to receive air from the intake opening; aconsole unit positioned adjacent to a forward end of the cab andconfigured to house an instrument display; and a heating, ventilationand air conditioning (HVAC) system comprising: a heat exchanger unitdisposed within the console unit so as to be positioned between theforward end and an aft end of the cab; a filter unit positioned betweena top surface of a wheel fender positioned on the outside of the cab andan adjacent wheel of the work vehicle, wherein the duct formed by thepillar is configured to direct the air from the intake opening of theroof to the filter unit; a blower configured to provide the air to theheat exchanger unit, wherein the blower is positioned on the floor ofthe cab, separate from the console unit, beneath or adjacent a seatwithin the cab; a floor-level conduit extending through at least aportion of the floor, wherein the floor-level conduit extends betweenthe blower and the heat exchanger unit; and a filter unit conduitextending between the filter unit and the blower.
 9. The cab of claim 8,comprising discharge vents mounted in the console unit to direct the airpassing through the heat exchanger unit toward an operator.
 10. The cabof claim 8, wherein the pillar is positioned next to a door of the cab.11. The cab of claim 8, wherein the filter unit has a clean box and adirty box separated from one another by a filter element, and the cleanand dirty boxes of the filter unit are housed within the wheel fender.12. The cab of claim 11, wherein the filter unit conduit is disposedwithin the cab, the filter unit conduit is configured to guide the airfrom the clean box to the blower, and the filter unit conduit curves tofollow a curved contour of the wheel fender.
 13. The cab of claim 11,comprising an access cover positioned adjacent to the top surface of thewheel fender, wherein the access cover is removable from the wheelfender to enable access to the filter element.
 14. The cab of claim 8,wherein the intake opening is formed along an underside of the roof ofthe cab.
 15. A cab of a work vehicle, comprising: a roof having anintake opening formed along a portion of the roof; a floor; a seatpositioned within the cab and configured to support an operator; aplurality of pillars, wherein a duct pillar of the plurality of pillarsextends between the roof and the floor, the duct pillar is positionedbetween a forward end pillar of the plurality of pillars and a back endpillar of the plurality of pillars, the duct pillar is configured tosupport the roof, and the duct pillar alone forms a duct configured toreceive air from the intake opening; a console unit positioned adjacentto a forward end of the cab and configured to house an instrumentdisplay; and a heating, ventilation and air conditioning (HVAC) systemcomprising: a heat exchanger unit disposed within the console unit so asto be positioned between the forward end and an aft end of the cab; afilter unit positioned between a top surface of a wheel fenderpositioned on the outside of the cab and an adjacent wheel of the workvehicle, wherein the duct formed by the duct pillar is configured todirect the air from the intake opening of the roof to the filter unit; ablower configured to provide the air to the heat exchanger unit, whereinthe blower is positioned on the floor of the cab, separate from theconsole unit, beneath or adjacent the seat; a floor-level conduitextending through at least a portion of the floor, wherein thefloor-level conduit extends between the blower and the heat exchangerunit; and a filter unit conduit extending between the filter unit andthe blower.
 16. The cab of claim 15, comprising discharge vents mountedin the console unit to direct the air passing through the heat exchangerunit toward the operator.
 17. The cab of claim 15, wherein the ductpillar is positioned next to a door of the cab.
 18. The cab of claim 15,wherein the filter unit has a clean box and a dirty box separated fromone another by a filter element, and the clean and dirty boxes of thefilter unit are housed within the wheel fender.
 19. The cab of claim 18,wherein the filter unit conduit is disposed within the cab, the filterunit conduit is configured to guide the air from the clean box to theblower, and the filter unit conduit curves to follow a curved contour ofthe wheel fender.
 20. The cab of claim 15, wherein the intake opening isformed along an underside of the roof of the cab.